Abstract:
This study was initiated in 1921 in cool temperate region. the soil is described as Prairie - Australian Great Soil Group (ref Stace HCT, Hubble GD, Brewer R, Northcote KH, Sleeman JR, Mulcahy MJ and Hallsworth EG (1968) A handbook of Australian Soil. Rellim Technical Publications, Glenside, South Australia. The land use and treatments in this ... experiment are as follows:

Time zero soil measurements taken. An attempt has been made to obtain a similar virgin soil by sampling soil from the trial fence-line boundary. This sample has been stored; sampling depth 0-15cm, measurements: OC%, total N%, P, mineral N (NO3 and NH4), pH, EC, Mg, Ca, K, Na

Details of soil sampling method: A soil corer for 0-15cm sampling made of steel & cylindrical in shape which takes a core of ca. 3cm diameter is used for surface soil coring. Typically 8-10 samples are taken over half of a rotation treatment plot (5x70m), and bulked. The plots have been split for nitrogen fertilizer application and so this is the reason why half of the rotation plot is the basic sampling area. Occasionally deep soil cores are collected using a pneumatic coring rig. Depending on soil depth this rig can core to 135-140cm or ca. 85 cm. Four core diameters are used with this rig, the diameter which is chosen is dependent upon the ease with which the soil core can be extracted from the coring tube. Diameters are 5cm, 2.5cm and 2.2cm. Between 2-4 cores are commonly extracted when deep coring across 1 half of a plot. Soil is separated into layers.

Details of measuring depths and soil layers: As stated due to soil depth variation across site, the depth to which coring is possible varies. There has been a range of different core depth segments collected on different occasions, e.g. May 1997 0-15, 70-80, 100-110, 130-135; October 1997 - 0-20, 20-40, 40-60, 60-80, 80-100, 100-120, 120-140. Deep coring has only occurred infrequently (no more than 4 times) over the entire trial duration over all the plots in the trial.

Nearest meteorological station to the site: Glen Innes Agricultural Research & Advisory Station which is 1 km from the site at coordinates 151 degrees 42 mins E, 29 degrees 42 mins S The meteorological station is manual.

All variables measured are listed in the parameters section of this record.

Description:
This url links to the GCTE-SOMNET home page where additional project information and methodology can be obtained. This site is currently in a datasharing phase of the network where actual data will become available shortly, at different levels of accessibility. Please follow this link for more information.

Width of smallest plot is 10 m Length of smallest plot is 70 m Width of largest plot is 10 m Length of largest plot is 70 m Slope: 4% . Shape: uniform Details of direction of cultivation: up and ... down slope Details of homogeneity of the plots: The primary variation is in soil depth with depth varying from 135 to 140cm to ca. 90cm in depth in plots 10,11,20 and 21

Details of replication, randomization and controls:

There are no replicates in the experiment. Having been designed in 1921, the trial is not replicated in space. Each of the phases of each rotation treatment is represented in the trial at any point in time. Treatment randomisation is absent. Replicate plots in treatment blocks

There are control plots described as follows:

Control plots have been included since 1994. In the years prior to 1994 (1921-1993) no control plots were used. Control plots are just a plot of soil, which is generally just been brought out of a permanent pasture and sown down to the crop to which it is being compared in the rotation at the time. These controls are designed to take out the rotation effects and just to zero in on season effects. Control plots are normally ca. 15mx40m

Refer to Norton et al 1995. The primary analysis to date has been of crop yields. The vast majority of the data from the trial is of crop yields. This data is of high integrity, and none has been eliminated when it was analyzed